Walter was born on the 7th May 1886 at Portstewart near Londonderry.
David Littler Jones tells us that he was the 5th son of seven boys. Their parents were Lt Com Robert Acheson Crombie Montagu and Annie Margaret Montagu (nee McMicking), of Crowmore, Portstewart, Co Londonderry.
Walter entered the Society of Jesus in 1903 and went to St Bueno’s College, Tremeirchion in 1915 to study theology. He was ordained early so he could join the forces as an army chaplain and was attached to the 22nd Brigade, Royal Garrison Artillery. He enlisted on the 17th March 1918 and served in France. He was wounded in his thighs and taken to the 45th casualty clearing station near Avoingt on 28th October. He died of his severe wounds on the 31st October 1918, just before the end of the war.
Walter Philip Montagu left a will. The England and Wales National Probate Calendar,( index of wills and administration) includes the following entry –
” Montagu. The Rev Walter of St Bueno’s College St Asaph, temporary chaplain HM Forces died 31st October 1918 in France or Belgium. Probate London 9 July to Rev Joseph Edward Blackett clerk. effects £1,166 ..11sh ..10d
He is buried in the British Cemetery at Avoingt. His younger brother, Alexander Cyril Montagu, a Lieutenant in the Royal Navy, was killed in an accidental explosion on the battleship HMS Bulwark off Skegness harbour on 26th November 1914 when over 750 crew members were killed.